Apparatus for preparing mercury dosing ampoules



March 21, 1950 F. G. LOPEZ APPARATUS FOR PREPARING MERCURY DOSING AMPOULES Filed June 22, 1944 j Zzq. i.

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BY J I ATTORNEY.

Patented Mar. 21, 1950 APPARATUS F OR PREPARING MERCURY DOSING AMPOULES Francisco Gonzalez Lopez, Buenos Aires, Argentina, assignor, by mesne assignments, to General Electric Company, Schenectady, N. Y., a corporation of New York Application June 22, 1944, Serial No. 541,514

2 Claims. 1

This invention relates to an apparatus for mak ing evacuated and hermetically sealed glass ampules, and more particularly'for preparing mercury dosing ampules utilized in the manufacture of electric discharge tubes.

In my co-pending U. S. application, Serial No. 540,770, filed June 17, 1944, now matured into Patent No. 2,415,895, issued on Feb. 18, 1947, I have explained in detail the advantages obtained in the manufacture of electric discharge tubes when evacuated and hermetically sealed glass ampules containing a small quantity of mercury are utilized for dosing the mercury filling Within these tubes.

The main object of the present invention is to provide a simple and effective means for producing the dosing glass ampules shown in my application referred to above.

The above and further objects of the invention will become more apparent from the following detailed description taken with reference to the ac companying drawings forming part of the specification and wherein:

'Fig 1 illustrates a plan view of the preferred embodiment of the apparatus for preparing mercury dosing glass ampules in accordance with the present invention.

Fig. 2 is an enlarged view of a longitudinal cross section of a. finished dosing glass ampule.

Referring now to the figures, it can be observed that the apparatus for preparing mercury dosing ampules comprises two mercury evaporators l0, each constituted of a vessel 10' the lower part of which, containing a supply of mercury is provided with a jacket |2 of heat-insulating material and is located in the interior of a coil l3. Coils |3 are connected in parallel to a high-frequency generator l4 through switching means l5 which may be manually operated or which may be designed to automatically maintain the connecthe inlet conduit 22 of a mercury diffusion pump 23 through another mercury trap 24.

As win the known high-vacuum pumping system, diffusion pump 23 is backed by a roughing pump 25 and is provided with a water cooling system having inlet and outlet conduits 26 and 21,- respectively. The degree of vacuum is controlled with a McLeod gauge or similar device schematically indicated with rectangle 28.

The upper part of vessels l0 has a neck 29 terminating in a thickened rim 30 to each of which the open ends of glass tubings 3| are sealed.

Before being sealed to rims 30 of vessels glass tubings 3| are closed at one end and their diameter is shrunk or constricted at substantially equal intervals so that the glass tubing is subdivided in a plurality of serially intercommunic-ating containers 32 which are transformed into mercury dosing ampules as will be explained hereinbelow.

After glass tubings 3| have been scaled to rims 30, stopcock 2| is turned to a position in which the interior of evaporators I0 and glass tubings 3| is connected to the exhausting system l1. Mercury pools or supplies are maintained at substantially room temperature and the exhaustion of glass tubings 3| is carried out until a pressure of approximately 5.10- mm. of Hg is obtained. stopcock 2| is then turned to its closed position to temporarily seal off mercury evaporators l0 and glass tubings 3|.

Switching means are now operated to connect the output of high-frequency generator I4 to coils l3 during a predetermined time interval and mercury within vessels I0 is heated by induction to evaporation temperature. The evaporated mercury penetrates into glass tubing 3| and is condensed on the interior surfaces of containers 32. Experience has shown that the condensed mercury is evenly distributed throughout the extension of glass tubings 3|, so that by sealing of! the shrunk portions of glass tubings 3|, containers 32 are transformed into dosing ampules each including a mercury drop 33, as shown in Fig. 2. Usually, glass tubings 3| will be first sealed off in the vicinity of rims 3|], so that new glass tubings can be sealed to evaporators l0 and the preparation of a new series of dosing ampules can be started, while the hermetically sealed glass tubings 3| are transformed into hermetically sealed dosing ampules, as explained hereinabove.

introduced in the particular organization shown and described without departing from the scope or my invention, as set forth in the appended claims.

I claim:

1. An apparatus for preparing mercury dosing ampules for electric discharge tubes, comprising at least one substantially perpendicularly disposed glass tubing closed at its upper end and having the diameter thereof shrunk at substantially equal intervals to form a plurality of serially intercommunicating containers, means to hermetically seal the open lower end of said glass tubing to a vessel including a mercury supply, means to communicate said vessel and glass tubing with exhausting means, means to temporarily seal off said vessel and said glass tubing after a predetermined degree of vacuum within said glass tubing has been obtained, means to inductively heat the mercury supply to fill said glass tubing with mercury vapour, and means to seal off said containers one by one after the mercury vapour has condensed in said glass tubing to produce evacuated and hermetically sealed dosing ampules containing substantially like quantities of mercury.

2. An apparatus for preparing mercury dosing ampules for electric discharge tubes, comprising a plurality of vessels each containing a mercury supply and located within a high-frequency heating coil, a plurality of substantially perpendicu- Number 4 larly disposed glass tubings closed at their upper ends and having the diameters thereot shrunk at substantially equal intervals to form serially intercommunicating containers, means to seal the open lower ends of said glass tubings to said vessels, means to communicate said vessels and,

glass tubings with a common exhausting means, means to temporarily seal on said vessels and the glass tubings sealed thereto after a predetermined degree of vacuum has been obtained, means to connect said heating coils to a common high-frequency generating means to inductively heat the mercury in said vessels and To fill the glass tubings with mercury vapour, and means to seal of! said containers one by one after the mercury vapour has condensed in said glass tubings to produce evacuated and hermetically sealed dosing ampules containing substantially equal quantities of mercury.

- FRANCISCO GONZALEZ LOPEZ.

REFERENCES CITED The following references are of record in the file of this patent:

Name Date 1,877,726 Noble Sept. 13, 1932 

